As about the double bond, two geometrical isomers are possible and the compound is having one chiral carbon so there are two optical isomers. It means it has total four stereo isomers.
$\mathrm{C}{\mathrm{H}}_3-\mathrm{C}\mathrm{H}=\mathrm{C}\mathrm{H}-\mathrm{*}\mathrm{C}\mathrm{H}\left(\mathrm{N}{\mathrm{H}}_2\right)-\mathrm{C}{\mathrm{H}}_3$
Total G.I = $2^{\mathrm{n}}=2^1=2$
Total O.I = $2^{\mathrm{n}}=2^1=2$
Here n = number of double bonds or number of chiral carbon atoms.